I had sex with my girlfriend for the first time 2 weeks before. I didn't use condom and at the time of sex I know that no sperms from me is released into her vagina. But now, usually periods will be normal and exactly will happen at the starting of the month but now this time it is being delayed. Whether sex caused this? And is there any possibility of forming pregnant, but I know upto my knowledge no sperms have been released out. Without knowing, is there any chance of releasing sperms into her. Am afraid of it.